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<h2>Description</h2>
<p class="Body"><span class="EmptyRef">TNotifiablePersistent</span> extends the standard 
  <span class="API">TPersistent</span> class with change notification events. That is, 
  it provides methods and events allowing its descendants to issue notification 
  on their changes. For example, <a href="../TBitmap32/_Body.htm">TBitmap32</a> 
  uses <a href="Events/OnChange.htm">OnChange</a> to notify its container (usually 
  <a href="../../../GR32_Image/Classes/TImage32/_Body.htm">TImage32</a> or <a href="../../../GR32_Layers/Classes/TBitmapLayer/_Body.htm">TBitmapLayer</a>) 
  that it was modified and its data has to be repainted to the screen. <span class="EmptyRef">TNotifiablePersistent</span>, 
  however, does not use or implement automatic change notification itself. This 
  is done in descendants.</p>
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